中间主应力对深部硬岩三轴卸荷破坏及能量特征影响分析  

Influence of Intermediate Principal Stress on Triaxial Unloading Failure and Energy Characteristics of Deep Hard Rock

作　　者：张鹿 李占金 李群 梁鹏 程豪杰 ZHANG Lu;LI Zhanjin;LI Qun;LIANG Peng;CHENG Haojie(College of Mining Engineering,North China University of Science and Technology,Tangshan,Hebei 063009,China)

机构地区：[1]华北理工大学矿业工程学院,河北唐山市063009

出　　处：《矿业研究与开发》2022年第1期127-132,共6页Mining Research and Development

基　　金：国家自然科学基金资助项目(51774138);河北省自然科学基金资助项目(E2021209131);河北省高等学校科技研究项目(QN2021111)。

摘　　要：为分析不同中间主应力对岩爆的影响,采用单面临空-五面受力的方式对深部花岗岩试件岩爆过程进行真三轴试验,对岩爆试件破坏特征、岩爆碎块粒径分布特点和岩石能量演化特性进行研究。结果表明,随着中间主应力的增大,首次出现颗粒弹射现象的时间点后延,而岩爆过程持续时间也相应变长;在中间主应力为10~40 MPa时出现岩爆坑,多表现为"V"型特征。岩爆坑尺寸和碎屑质量随中间主应力的增大而增大,岩石碎屑质量微粒与细粒所占百分比呈上升趋势,粗粒呈下降趋势;在岩爆试验过程中,中间主应力的增大使得岩石在峰值前试件岩爆破坏过程释放的能量增多。岩石在峰值应力处的总能量U、弹性应变能U;、耗散能U;与耗散能比例U;/U随中间主应力的增大而增大。研究成果为进一步探讨深部三向应力环境下硬岩岩爆机理提供参考依据。In order to analyze the influences of different intermediate principal stresses on the rockburst, the mode of single-face overhanging and five-ace forcing was used to carry out true triaxial test on the rockburst process of deep granite specimens. The failure characteristics of rockburst specimens, the particle size distribution characteristics of explosive fragments and the energy evolution characteristics of rocks were studied. The test results show that as the intermediate principal stress increases, the time point for the first particle ejection phenomenon is delayed, and the duration of the rockburst process is correspondingly longer. In the range of intermediate principal stress of 10~40 MPa, rock burst pits appear, which mostly show the “V” type characteristics. The size of rock burst pit and debris mass increase with the increase of intermediate principal stress, and the percentage of debris mass particles and fine particles of rock increases, while the coarse particles decrease. It is found that in the process of rockburst test, the increase of intermediate principal stress makes the more energy released in the process of rock burst before the peak value. When the total energy U, elastic strain energy U;, dissipated energy U;and dissipated energy ratio U;/U are at the peak value, they increase with the increase of intermediate principal stress. The research results are of scientific value to further explore the rockburst mechanism of hard rock under a deep three-direction stress environment.

关 键 词：真三轴 岩爆 中间主应力 破坏特征 能量演化 

分 类 号：TD311[矿业工程—矿井建设]